Energy-Budget Analysis for Phased-Array Radar with Optimum Beamforming

We extend the radar-equation used to determine detection performance for the case of radar systems that employ phased-array receiving arrangements incorporating optimum beamforming. The method described uses electromagnetic modelling of the radar receiver antenna-array to determine the energy transfer between the signal and noise impinging on the array and the energy entering the digitising receivers on the terminals of each antenna element. We determine calibrated signal and noise levels associated with the optimum beamformer throughout the energy-budget. Budget loss allowance now includes a term for the loss in the overall target signal-to-noise ratio for any particular beamformer solution compared to the optimum beamformer solution. The method is particularly suitable for external noise limited radar systems, such as high-frequency radars, where the noise is often spatially non-uniform across their field of regard.